Gears of War 4 takes place 25 years after the Imulsion Countermeasure weapon destroyed both the Locust, Lambent and Imulsion. Unfortunately this also knocked out fossil fuels, forcing humanity to adapt new ways for survival. This also caused Windflares; powerful windstorms that form across the planet. Following the aftermath of the Lambent Epidemic, the reformed Coalition of Governments estimated that hundreds of thousands of humans are left on Sera. To prevent the population from declining, cities that are walled in were built to protect the citizens from the dangers outside.